A dog can smell volatile olfactory compounds (VOCs) emitted by cancer cells and then is taught to alert its trainer. Scientists have known for a few decades now that the dog’s highly developed sense of smell could be used to diagnose cancer. In 1989, the first report of spontaneous detection of melanoma in humans by untrained dogs was published. The dogs’ peculiar behaviour (sniffing, licking, attempting to bite off the mole) alerted their owners to go to their doctor and get checked out. Since then actual research institutes have been formed that focus on training these “medical detection dogs.”

A study published in 2011 in Germany found that dogs could detect lung cancer in 71% accuracy, and a recent project from the University of Pennsylvania demonstrated that a lab named Ohlin could detect ovarian cancer with 100% accuracy. Scientists are trying to isolate the VOCs detected by dogs and some companies are even trying to develop electronic sniffers to detect them.

Perhaps the next standard in cancer diagnosis will be based on your four legged friend’s expert sniffing abilities.